172 r. T. CLEVE, SYNOPSIS OF, THE NAVICULOID DIATOMS, " 



Fresh water: Sweden (Uppland to Skaiie, Grothlaiul, Gulf of Bothnia)! Finland! Hol^tein! 

 England! Belgium (V. H.), Germany! -Switzerland! Italy! Mouth of Jenissey! Japan! Australia 

 (Lake Muir)! New Zealand! New York! Argentina! 



Cj/nih. affiiiis is a variable species, connecting Cymh. turgidula with Cij}nh. parva. The 

 ventral margin is sometimes indented in the middle. Such a form has been figured by Grunow in 

 Foss. Diat. Osterr. Ung. PI. XXIX f. 2(5 and is probably identical with Cijmh. cxisa var. major 

 GuTwiNSKY Materialy p. 25 PL I f. 21. 



50. C. parvji A^^ Sm. (1852). — V. semilanceolate, with slightly rostrate, obtuse to sub- 

 truncate ends. L. (),():! to (),0 5; B. 0,01 to 0,oi2 mm. Median line somewhat arcuate and broad 

 (oblique). Axial area narrow, very slightly dilated in the middle. Striae 9 or 10 (median, dorsal) 

 to 13 (ventral and terminal) in 0,oi mm., very slightly radiate, obscurely punctate. There is no 

 punctum on the ventral side of the central nodule. — Cocco. parvmn W. Sm. B. D. I p. 77. PI. 

 XXIII f. 222. A. S. Atl. X f. 14, 15. Grun. Franz Josephs Land J), p. 97 (45) PL I f. 9. Cymh. cymhy- 

 formis var. parva V. H. Syn. p. (i4 PL II f. 14. Coccouemn pachyccplialum Rabii. Alg. Eur. 

 N:o 1107 (1861). 



Fresh water: Greenland! Franz Josephs Land (Grun.), Sweden (Lapland to Skane)! Norway 

 (Finmark to Christiania)! Finland! England! Germany! Belgium! France! Switzerland! Savoy! 

 Italy! Mouth of Jenissey! North America, Winnepeg! 



Var. huiiyarka Gkun. (1875). — L. 0,024 to 0,04; B. (),»)()'.i to 0,01 mm. Area dilated on 

 the dorsal side of the central nodule. Stria; 10 in O.d 1 mm. — Coccon. /nfiif/aric. Grun. in A. S. Atl. 

 IX f. 38, X f. 16, 17; LXXI f. 37, 38. 



Fresh water: Norway (Brevig)! Flatten See, Hungary (Grun.). 



Cyml). parva is in the living state stipitate. It is closely akin to Cymh. affinis and 

 Cymh. cymhiformis, differing from both by the want of a punctum at the end of the median 

 central stria. 



51. C. IJotollus Lagst. (1873). — V. arcuate, with parallel margins and rounded ends. 

 L. 0,024 to 0,034; B. 0,006 to 0,007 mm. Median line slightly excentric, arcuate. Axial area 

 narrow, not dilated around the central nodule. Stria) 10 to 11 in 0,oi mm., very slightly radiate, 

 not distinctly punctate. — Cymh. variahilis var. Botellus Lagst. Spitsb. I), p. 44 PL II f. 22. 

 Cymh. hot. A. S. Atl. LXXI f. 39. 



Fresh water: Arctic America! Beeren Eiland (Lagst.), Spitzbergen! 



52. €, cymbiformis (Ag. 1830?) Ivutz. (1833). — V. boat-shaped, with straight, sometimes 

 slightly gibbous, ventral margin and obtuse or truncate ends. L. 0,o.'> to 0,i; B. O.oi to 0,012 

 mm. Median line slightly arcuate, broad (oblique); its terminal fissures reflexed. Axial area 

 narrow; central area small. Striai 8 to 9 in 0,oi mm. somewhat closer at the ends, finely lineate 

 (lineoUe 20 in 0,oi mm.). On the ventral side of the central nodule is an isolated punctum at the 

 end of the median stria. — Ag. Consp. ]). 10 (1830)? Frusttdia coffeoe formis KtJTZ. Dec. N:o 11 

 (1833) according to Lagst. Frust. cymh.[ KuTZ. Linn. VIII p. 539 PL XIII f. 10. Coccon. cymhi- 

 forme W. Sm. B. D. I p. 76 PL XXIII f. 220? A. S. Atl. IX f. 76 to 79; X f. 13. Cymh. cymhif. 

 V. H. Syn. p. 63 PL II f. 11 a, b, c. 



Fresh water: Iceland! Norway (Finmark to Brevig)! Sweden! Finland! England! Belgium 

 (V. H.), France! Germany! Switzerland! Hungary (Dubravica, foss. Grun.), Socotra (Ivittou), Japan! 

 Tasmania! Argentina! 



C. cyrnhifor))iis is very similar to C. helvdica, but differs by the reflexed terminal fissures 

 and from C. helvetica, as well as from C. j^arva., by the isolated punctum below the central nodule. 



53. C. Beccarii Grun. (1886). — V. clavate, and at the same time boat-shaped, with one 

 half longer than the other. L. 0,0.54 to 0,ot;; 1^. 0,oi4 mm. Median line arcuate, almost in the 

 iiiiddlf of the valve. Axial area imrrow, ]iot dilated around the central nodule. Stri;e 11 to 16 



